Fractional First Officer reported entering a VFR pattern altitude appropriate for jet aircraft; but was informed by ATC that the correct altitude was lower. Reporter noted the pattern altitude for jets was not listed on any VNY charts and needed to be addressed.

Narrative

I; Person A; was acting as SIC/pilot monitoring sitting right seat on a ferry flight from ZZZ to VNY. We were vectored into the downwind for Runway 16R. We were brought down to 5000 feet and asked if we were able to see the airport. We called the airport in sight and were cleared for the visual approach.The PIC/pilot flying was Person B. Upon being cleared for the visual Person B started a slow descent due to the terrain and multiple GA aircraft flying in the area. As we turned to final we were high due to aircraft avoidance and terrain avoidance. On final there was also a helicopter that was coming into our approach enough that we were alerted to it but did not receive an RA. During the brief for the approach it was determined pattern altitude would be 2300 feet as VNY [was] 802 feet in elevation.Person B called for a go-around due to our high altitude and we began the climb out. I could see another aircraft headed into Burbank and was about to point it out to Person B when we received an RA. Person B responded to the RA and descended. I believe we were 2100 - 2200 feet when we received the RA. Once the RA was complete we conducted a pattern and landed without issue. During the go-around Tower was questioning why we were going around. Whole responding to Tower we received the RA. While responding to the RA Tower informed us of the traffic and pattern altitude was 2000 feet. Person B descended to 2000 feet. Tower asked if we had to descend or climb for the RA. After informing them of the descent were given instructions for the pattern and landing.Person B and I both questioned the 2000-foot pattern altitude as we had not observed that in the Jeppesen charts or on FOQA chart. We both went through the charts separately and could find no information on the pattern altitude being 2000 feet. I personally have ForeFlight so I checked that. In ForeFlight's information for VNY I located the 2000-foot pattern altitude but it did not specify jets. So even if we would've observed this in ForeFlight we still would've gone with 2300 feet as it is 1500 feet above AGL. Suggestions: I have been to this airport multiple times. There is always a large amount of GA and helicopter traffic. We were kept high due to all of this traffic and on top of it had a helicopter give us a traffic warning on approach.The pattern altitude for jets is not listed on any charts and needs to be addressed.